China is not Antipodal (Diametrically Opposite) to the United States.

Why do so many Americans think it is?

This Wikipedia article:

has this to say:

“The China syndrome (loss-of-coolant accident) is a hypothetical nuclear reactor operations accident characterized by the severe meltdown of the core components of the reactor, which then burn through the containment vessel and the housing building, then (figuratively) through the crust and body of the Earth until reaching the opposite end, presumed to be in “China” (though the antipodes of (sic) continental (sic) U.S. are in fact located in the Indian Ocean).[33][34] The phrasing is metaphorical; there is no way a core could penetrate the several-kilometer thickness of the Earth’s crust, and even if it did melt to the center of the Earth, it would not travel back upwards against the pull of gravity. Moreover, any tunnel behind the material would be closed by immense lithostatic pressure. Furthermore, China does not contain the antipode of any landmass in North America.”

I agree. Ignoring some typos and the incorrect use of “continental” rather than “contiguous” (Alaska is on the continent of North America), this is spot on.

China is entirely within the northern hemisphere, as is the United States, and since the antipodal point of a point in the northern hemisphere is a point in the southern hemisphere it’s very clear and easy to understand. Argentina and Chile are antipodal to China, not any part of the United States. It’s not hard to grasp.

This Wikipedia article may be of interest, nevertheless (you heard it first here, right?):

As an aside, I find it worrying that a misconception like this could be mentioned in the same breath as something where it is so important not to make even the tiniest mistake: the nuclear industry. I hope nuclear engineers did not originate or popularize this misconception.

Why do Americans (and a good few other people) tend to think of China as being antipodal the the United States? At a guess, it because the actual antipodal points of the contiguous United States, as stated in the Wikipedia quote are in the Indian Ocean which not many Americans are familiar with and because China, which Americans are familiar with (or at least have heard of) is almost exactly 180 degrees east (and west) of the contiguous United States, it other words, almost exactly half way *around* the world.

Besides the problem of Americans not being familiar with the Indian Ocean and where exactly it is, there are a number of other advantages to saying “the nuclear reactor would melt its way all the way to China” or with saying “dig a hole all the way to China” which I think was an earlier notion viz. melting a hole all the way to the Indian Ocean doesn’t sound as bad, because there aren’t any people there, and the seawater might even start flowing down the hole which complicates the scenario very inconveniently. Likewise “dig a hole to the Indian Ocean”. The listener is likely to start thinking about how exactly that would work, and start getting skeptical, or irritated, or at least distracted.

This means that the US and China kind of change places in space every half (sidereal) day as the earth rotates on its axis.

China is on almost exactly the same set of latitudes as the contiguous United States, and is about ten percent greater in area. This makes it easy to remember and visualize where China is. Even better, the contiguous United States straddles the 90th meridian west while China straddles the 90th meridian east. To put it another way, the two are equidistant from the prime meridian.

Another way to say it is: China is the image of contiguous United States when rotated 180 degrees around the north pole. Or: China is the “reflection” of the contiguous US in the north pole, if you see what I mean.

Thus you could say that the contiguous US and China are diametrically opposite each other on the parallel (line of latitude) that they share. I am guessing someone confused being on the opposite side of a line latitude for being on the opposite side of the globe.

In fact, the contiguous US and China are cut by the 45th parallel on the their northern borders. They look to me like a pair of irregular pieces of cloth pegged to straight washing line that is the 45th parallel, and this helps me recall where they are. It’s just one of many interesting thing about that parallel that I have noticed since memorizing it.

Here is a Wikipedia article with a map of the world showing the 45th parallel:

I published an article recently describing a novel mnemonic I created in order to memorize the 45th parallel:

My favorite activity is learning new things.